Cavitation erosion (CE) is caused by the formation and collapse of vapor bubbles in a liquid near a metallic component surface. For example, FIG. 1 provides a series of figures in which the cavitation erosion mechanism is shown. In FIG. 1a, a vapor bubble ‘b’ forms on an outer film ‘f’ that is present on a surface of a matrix material ‘m’. Upon collapse of the vapor bubble b as illustrated in FIG. 1b, the film f experiences a local failure or opening ‘o’. In addition, a small defect ‘d’ can be formed within the matrix material ‘m’ and the film ‘f’ may or may not form over the defect site as shown in FIG. 1c. The defect site ‘d’ can act as or is prone to the formation of additional vapor bubbles ‘b’ (FIG. 1d), which when the bubble ‘b’ collapses (FIG. 1e) produces another opening ‘o’ within the surface film ‘f’ and additional damage via defect site ‘d’ to the matrix material ‘m’ occurs (FIG. 1f). Once such a defect site ‘d’ is formed, pitting attack can also occur at such a location.
It is appreciated that CE can occur in equipment that processes, uses and/or is subjected to high pressure liquid. In addition, high pressure hydraulic pumps used in various industries, such as the automotive industry, have experienced a gradual increase in pressure requirements, and thus an increase in the susceptibility to CE. As such, there is an ever-increasing need for materials that provide improved CE resistance.
It is known from empirical studies, metallic materials with high hardness and low second phase precipitates have been found useful in CE susceptible environments. However, it is also known that the presence of second phase precipitates can enhance the hardness of a material and thus possibly provide increased CE resistance. However, in order to empirically determine whether or not which second phase precipitates can actually improve CE resistance, CE testing for each combination of metallic material with second phase precipitates would have to be conducted. The same is true for whether or not other microstructural features such as grain size, grain orientation, etc., can provide increased CE resistance. Yet such testing takes time and can be expensive. Therefore, a process for designing metallic materials for CE resistance which does not require empirical testing over a wide range of microstructural features would be desirable.